Data collection for a multicenter randomized controlled double blind clinical trial of barbiturate coma in intractable hypertension began on October 1, 1982. A study designed to derive a profile of the traumatic spinal cord injured patient began on January 1, 1983. Neuropsychological and psychosocial data is being collected on mildly head injured patients to study the cognitive impact and subsequent natural history of mild head injury in different populations. Studies being continued or completed include: an analysis of cognitive outcome of severe and moderate head injury; analysis to characterize demographic and clinical features; and studies of the features influencing outcome.